For many years, architects, construction workers, boaters and similar personnel have had a need for an effective lightweight, portable storage/display device for use in protecting construction drawings, marine charts and the like from adverse weather and environmental conditions while, at the same time, permitting both: (i) ease of reference to such documents when needed without exposure to the elements; and (ii), compact protected storage thereof when not in use. Many approaches have heretofore been suggested in an effort to solve this problem; but, despite these efforts, prior to the advent of the present invention no simple, effective storage/display device has found widespread acceptance. For example, a very early approach is that disclosed in U.S. Pat. No. 596,300--Lee, wherein the patentee provides an envelope formed of a cardboard stiffened, rubber-coated, nonrollable backing member and a transparent face formed of celluloid with the two envelope defining components being rollable along one edge so as to seal the access opening while permitting reference to the chart or other document contained within the envelope through the celluloid face.
In U.S. Pat. No. 2,293,979--Hopkins, the patentee discloses a portable map case having a flexible waterproof sheath formed of leather or the like and which is capable of being rolled into and from a tubular configuration with the device having a pair of transparent sheets carried therein which permit of placement of a map, with or without a superimposed sheet of tracing paper, therebetween. As in the aforesaid Lee patent, the device is intended to display only a single document at a time.
Corley U.S. Pat. No. 2,346,908 discloses a flexible roll-up drawing board comprising a relatively complex construction including a plurality of rigid slats secured to a canvas backing member and a transparent sheet of flexible material removably secured thereto by a circumferential zipper mechanism. In a subsequently issued patent--viz., U.S. Pat. No. 2,661,570--Corley discloses a modified version of a roll-up map case in which the zipper is deployed along one edge only of the transparent envelope defining sheet, with the remaining edges being permanently secured to the flexible canvas backing and rigid slat arrangement.
In U.S. Pat. Nos. 2,294,276--Callinicos and 4,157,626--Bedinghaus, the patentees disclose rather rigid plate-like display devices having transparent faces for protecting maps, charts and the like. In the Bedinghaus patent, the chart may be off-rolled from a roll adjacent one edge of the device and simultaneously on-rolled about a second parallel roll at the opposite edge of the device, thereby permitting inspection of a selected region of a relatively long, continuous document having a length considerably greater than the width of the transparent holding device.
Other prior patents of general interest include U.S. Pat. No. 1,623,806--Nienhauser pertaining to a roll-up tissue paper package; and, U.S. Pat. No. 3,270,791--Harris relating to a roll-up fabric storage device.
However, notwithstanding the foregoing prior disclosures, there has been no simple, effective storage/display device characterized by its ability to maintain a plurality of documents in a sealed weathertight environment at all times, yet wherein any given document may be immediately and fully displayed while being maintained in a weathertight environment; and, wherein the entire package can be rolled into a tight, compact, tubular helix for ease of portability and/or compact storage when not in use.